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Title: Fast Fact and Concept #28: Subcutaneous Infusions
Author(s): Weissman, David E
SUBCUTANEOUS OPIOID INFUSIONS
An intravenous opioid infusion is the standard of care for managing moderate-severe pain or dyspnea when the oral/rectal route is unavailable or frequent dose adjustments are needed. However, IV infusions have the burden of needing intravenous access. As death nears, the burden of maintaining IV access, especially in the home setting, can be enormous. An alternative well known among hospice professionals, but little appreciated in other care settings, is the subcutaneous (SQ) route for continuous, PCA or intermittent opioid injections (1,2).
Drugs
Morphine, hydromorphone (Dilaudid), fentanyl and sufentanil can all be safely administered as a continuous SQ infusion.
Dosing equivalents
SQ dosing is equivalent to IV; a 3 mg/hr IV morphine infusion is equal to an 3 mg SQ infusion.
Pharmacokinetics
SQ infusions can produce the same blood levels as chronic IV infusions. There is no data to suggest that cachectic, febrile or hypotensive patients have problems with drug absorption (3).
Volume and Drug Choice
The limiting feature of a SQ infusion is the infusion rate; in general, SQ tissue can absorb up to 3 cc/hr; for higher volumes hyaluronidase (Wydase) can be administered. At low opioid requirements morphine is the drug of choice; a switch to hydromorphone is indicated for a high opioid requirement due it's higher intrinsic potency (6:1), thus the need for a smaller infusion volume.
Administration
Use a 25 or 27 gauge butterfly needle-place on the upper arm, shoulder, abdomen or thigh. Avoid the chest wall to prevent iatrogenic pneumothorax during needle insertion. The needle can be left indefinitely without site change unless a local reaction develops-typically, patients can keep the same needle in place for up to one week at a time.
Toxicity
Local skin irritation, itching, site bleeding or infection can occur; of these, skin irritation is the most common, easily treated by a needle site change.
Patient acceptance
Patients readily appreciate the ease of SQ administration as an alternative to IV access.
Also See:
Fast Fact #54: Opioid Infusions
References
Bruera E, Brenneis C, Michaud M, et al. Use of the subcutaneous route for the administration of narcotics in patients with cancer pain. Cancer 1988;62:407-411.Disclaimer: Fast Facts provide educational information, this information is not medical advice. Health care providers should exercise their own independent clinical judgment. Some Fast Fact information cites the use of a product in dosage, for an indication, or in a manner other than that recommended in the product labeling. Accordingly, the official prescribing information should be consulted before any such product is used.
Creation Date: 11/2000
Format: Handouts
Purpose: Instructional Aid, Self-Study Guide
Audience(s)
| Training: Fellows, 3rd/4th Year Medical Students, PGY1 (Interns), PGY2-6, Physicians in Practice |
| Specialty: Anesthesiology, Emergency Medicine, Family Medicine, General Internal Medicine, Geriatrics, Hematology/Oncology, Neurology, OB/GYN, Ophthalmology, Pulmonary/Critical Care, Pediatrics, Psychiatry, Surgery |
| Non-Physician: Nurses |
ACGME Competencies: Medical Knowledge, Patient Care
Keyword(s): Addiction, Chronic non-malignant pain, Controlled substance regulations, Pain, Pain assessment, Pain treatment
The Fast Facts series is distributed for educational use only and does not constitute medical advice. For the most current version of Fast Facts visit the EPERC web site at www.eperc.mcw.edu. This mirror version is provided subject to copyright restrictions for educational use within the Inter-Instutional Collaborating Network on End-of-Life Care (IICN).